Antigen Production Research Articles

Dysfunctional β-cell autophagy induces β-cell stress and enhances islet immunogenicity

BackgroundType 1 Diabetes (T1D) is caused by a combination of genetic and environmental factors that trigger autoimmune-mediated destruction of pancreatic β-cells. Defects in β-cell stress response pathways such as autophagy may play an important role in activating and/or exacerbating the immune response in disease development. Previously, we discovered that β-cell autophagy is impaired prior to the onset of T1D, implicating this pathway in T1D pathogenesis.AimsTo assess the role of autophagy in β-cell health and survival, and whether defects in autophagy render islets more immunogenic.MethodsWe knocked out the critical autophagy enzyme, ATG7, in the β-cells of mice (ATG7Δβ-cell) then monitored blood glucose, performed glucose tolerance tests, and evaluated bulk islet mRNA and protein. We also assessed MHC-I expression and presence of CD45+ immune cells in ATG7Δβ-cell islets and evaluated how impaired autophagy affects EndoC-βH1 HLA-I expression under basal and IFNα stimulated conditions. Lastly, we co-cultured ATG7Δβ-cell islet cells with diabetogenic BDC2.5 helper T cells and evaluated T cell activation.ResultsWe found that all ATG7Δβ-cell mice developed diabetes between 11-15 weeks of age. Gene ontology analysis revealed a significant upregulation of pathways involved in inflammatory processes, response to ER stress, and the ER-associated degradation pathway. Interestingly, we also observed upregulation of proteins involved in MHC-I presentation, suggesting that defective β-cell autophagy may alter the immunopeptidome, or antigen repertoire, and enhance β-cell immune visibility. In support of this hypothesis, we observed increased MHC-I expression and CD45+ immune cells in ATG7Δβ-cell islets. We also demonstrate that HLA-I is upregulated in EndoC β-cells when autophagic degradation is inhibited. This effect was observed under both basal and IFNα stimulated conditions. Conversely, a stimulator of lysosome acidification/function, C381, decreased HLA-I expression. Lastly, we showed that in the presence of islet cells with defective autophagy, there is enhanced BDC2.5 T cell activation.ConclusionsOur findings demonstrate that β-cell autophagy is critical to cell survival/function. Defective β-cell autophagy induces ER stress, alters pathways of antigen production, and enhances MHC-I/HLA-I presentation to surveilling immune cells. Overall, our results suggest that defects in autophagy make β-cells more susceptible to immune attack and destruction.

Identification of glycogen synthase kinase 3alpha/beta as a host factor required for hepatitis B virus transcription using high-throughput screening.

Hepatitis B virus (HBV) leads to severe liver diseases, such as cirrhosis and hepatocellular carcinoma. Identification of host factors that regulate HBV replication can provide new therapeutic targets. The discovery of sodium taurocholate cotransporting polypeptide (NTCP) as an HBV entry receptor has enabled the establishment of hepatic cell lines for analyzing HBV infection and propagation. Using this new system, studies aimed at identifying host factors that regulate HBV propagation have increased. We established an HBV-based-reporter gene expression system that mimics HBV replication from transcription to virus egress. Using this approach, we screened 1,827 Food and Drug Administration-approved compounds and identified glycogen synthase kinase 3 (GSK3)alpha/beta inhibitors, including AZD1080, CHIR-98014, CHIR-98021, BIO, and AZD2858, as anti-HBV compounds. These compounds suppressed hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) production in HBV-infected human primary hepatocytes. Proteome analysis revealed that GSK3alpha/beta phosphorylated forkhead box K1/2 (FOXK1/2)s. A double-knockout of FOXK1/2 in HBV-infected HepG2-NTCP cells reduced HBeAg and HBsAg production. The rescue of FOXK2 expression, but not FOXK1 expression, in FOXK1/2-double-knockout cells restored HBeAg and HBsAg production. Importantly, phosphorylation of FOXK2 at Ser 424 is required for GSK3alpha/beta-mediated HBeAg and HBsAg production. We observed the binding of FOXK2 to HBV DNA in HepG2-NTCP cells. Our recombinant HBV-based screening system enables the discovery of new targets. Using our approach, we identified GSK3 inhibitors as potential anti-HBV agents.

Fitness costs of Mycobacterium tuberculosis resistant to rifampicin is compensated by rapid Th2 polarization mediated by early and high IL-4 production during mice infection

It was a general belief that drug resistance in Mycobacterium tuberculosis (Mtb) was associated with lesser virulence, particularly rifampicin resistance, which is usually produced by mutations in the RNA polymerase Beta subunit (RpoB). Interestingly, this kind of bacterial mutations affect gene transcription with significant effects on bacterial physiology and metabolism, affecting also the bacterial antigenic constitution that in consequence can produce diverse immune responses and disease outcome. In the present study, we show the results of the Mtb clinical isolate A96, which is resistant to rifampicin and when used to infect BALB/c mice showed hypervirulence, apparently by rapidly polarization of the Th2 immune response through early and high production of IL-4. The 2D-PAGE analysis of the secretome of Mtb A96 showed 204 spots, and by immunoproteome, seven proteins that were differentially recognized with the sera of infected mice on day 28 were identified by LC-MS/MS. The proteins correspond to surface antigens, virulence factors, and energy metabolism enzymes. Some of them are immunodominant antigens, such as LpqH lipoprotein that induces IL-4 secretion in cell suspensions from the lung and spleen of mice infected with Mtb A96 at 28 days postinfection, suggesting that LpqH could be one of the main antigens involved in the Th2 polarization. The reduction of Mtb A96 hypervirulence in IL-4Rα−/− BALB/c mice highlights the importance of IL-4 induction and Th2 response polarization and the immunopathological response. Thus, high and rapid bias to Th2 response is a mechanism of Mtb virulence, which could be mediated by rifampicin-resistant Mtb isolates, probably by high production and secretion of specific antigens.

Pediatric blepharokeratoconjunctivitis: A challenging ocular surface disease.

Pediatric blepharokeratoconjunctivitis (PBKC) is a chronic and recurrent ocular surface inflammatory disorder affecting children in early life. It is frequently under- or late- diagnosed, representing a potential cause of severe visual morbidity worldwide. An expert panel consensus recently agreed on its definition and proposed diagnostic criteria for suspected and definitive PBKC to reduce confusion and avoid varied terminology previously used in the literature, improving early and precise diagnosis. Previous evidence has pointed to the role of the adaptive immune system in recognizing and handling antigenic eyelid bacterial products, particularly from the cell wall, and the direct toxic and inflammatory effects of their cytolytic exotoxins on the ocular surface. PBKC is a frequent referral in pediatric and cornea clinics characterized by a history of recurrent chalazia, blepharitis, meibomian gland dysfunction, conjunctival hyperemia, phlyctenules formation, and corneal infiltrates with vascularization and scarring. The latter is a major cause of significant visual loss and amblyopia. Current treatment strategies aim to control inflammation on the ocular surface, halt disease progression, and avoid corneal involvement. Further research on pathogenic mechanisms will shed light on novel potential therapeutic strategies. Awareness of PBKC should enhance early diagnosis, prompt adequate treatment, and improve outcomes. We compile current evidence on epidemiology, pathophysiology, clinical spectrum of disease, diagnostic criteria, and management strategies for PBKC.

Plant-Based Antigen Production Strategy for SARS-CoV-2 Nucleoprotein and RBD and Its Application for Detection of Antibody Responses in COVID-19 Patients

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the development of efficient serological tests for monitoring the dynamics of the disease as well as the immune response after illness or vaccination was critical. In this regard, low-cost and fast production of immunogenic antigens is essential for the rapid development of diagnostic serological kits. This study assessed the plant-based production of nucleoprotein (N) of SARS-CoV-2 and chimeric receptor-binding domain (RBD) of SARS-CoV-2 presented by hepatitis E virus capsid (HEV/RBD) and validation of the plant-derived proteins as diagnostic antigens for serological tests. The target proteins were expressed in and purified from Nicotiana benthamiana plants. The resulting yield of chimeric HEV/RBD protein reached 100 mg/kg fresh weight and 30 mg/kg fresh weight for N protein. The purified N protein and HEV/RBD protein were used to develop an indirect enzyme-linked immunosorbent assay (iELISA) for the detection of antibodies to SARS-CoV-2 in human sera. To validate the iELISA tests, a panel of 84 sera from patients diagnosed with COVID-19 was used, and the results were compared to those obtained by another commercially available ELISA kit (Dia.Pro D. B., Sesto San Giovanni, Italy). The performance of an HEV/RBD in-house ELISA showed a sensitivity of 89.58% (95% Cl: 75.23–95.37) and a specificity of 94.44% (95% Cl: 76.94–98.2). Double Recognition iELISA based on HEV/RBD and N protein is characterized by a lower sensitivity of 85.42% (95% Cl: 72.24–93.93) and specificity of 94.44% (95% Cl: 81.34–99.32) at cut-off = 0.154, compared with iELISA based on HEV/RBD. Our study confirms that N and fusion HEV/RBD proteins, which are transiently expressed in plants, can be used to detect responses to SARS-CoV-2 in human sera reliably. Our research validates the commercial potential of using plants as an expression system for recombinant protein production and their application as diagnostic reagents for serological detection of infectious diseases, hence lowering the cost of diagnostic kits.

A broad spectrum Shigella vaccine based on VirG53–353 multiepitope region produced in a cell-free system

Dysentery caused by Shigella species remains a major health threat to children in low- and middle-income countries. There is no vaccine available. The most advanced candidates, i.e., O-polysaccharide (OPS)-based conjugates, have limited coverage—only against the immunizing serotype. Vaccines based on Shigella conserved proteins are sought for their simplicity and capacity to prevent disease caused by multiple serotypes. We previously reported the broad protective capacity of VirGα, a conserved surface-exposed domain of Shigella virulence factor. Seeking to refine the vaccine antigenic target and achieve scalable manufacturing compatible with Good Manufacturing Practices, we mapped linear B-cell epitopes spanning the entire VirG protein sequence by probing the immune reactivity of 10-mer peptides (overlapping 4–8 aa) with sera from Shigella-infected rhesus monkeys. The surface-exposed VirG53–353 subregion of the passenger α-domain demonstrated the highest and strongest immunoreactivity. VirG53–353 was produced efficiently at a large scale (>150 mg/L) using cell-free protein synthesis. When administered to mice intramuscularly, VirG53–353 elicited robust antibody responses and conferred high levels of protection against the three most prevalent Shigella serotypes (S. flexneri 2a, 3a, and S. sonnei). VirG53–353 evoked the production of Th2-type cytokines by spleen cells from vaccinated mice. A new universal Shigella vaccine based on VirG53–353 meets the World Health Organization’s preferred product specifications. The target antigen refinement and production improvement described here will facilitate the first-in-human studies.

Transient Expression of Zika NS2B Protein Antigen in Nicotiana benthamiana and Use for Arboviruses Diagnosis.

Zika (ZIKV) and Dengue (DENV) viruses are clinically significant due to their severe neurological and hemorrhagic complications. Rapid diagnostics often rely on nonstructural proteins to generate specific antibodies. This study aimed to produce IgG antibodies from the recombinant ZIKV protein and plant-expressed NS2B protein for arbovirus detection in serum and urine samples. The NS2B protein was expressed in Nicotiana benthamiana and purified chromatographically. Validation of recombinant NS2B as an antigen in indirect immunoassays demonstrated 95% sensitivity and 100% specificity in IgM/IgG ELISA tests, enabling effective detection of ZIKV and DENV. Notably, r-ZIKV-NS2B IgG identified positive ZIKV and DENV cases in urine but failed to detect negatives, suggesting limitations in specificity for urine diagnostics. Using urine as a diagnostic medium offers a less invasive and more practical approach, broadening the test applicability. This study utilized patient-derived positive urine samples and healthy samples spiked with an exogenous virus. Findings highlight the potential of the ZIKV-NS2B protein as a robust antigen for arbovirus diagnosis and demonstrate the viability of plant-based systems for antigen production, advancing diagnostics for neglected tropical diseases.

Self-amplifying RNA virus vectors for drug delivery.

Viral vectors have proven useful for delivering genetic information, such as drugs and vaccines, for therapeutic and prophylactic interventions. Self-amplifying RNA viruses possess the special feature of high-level RNA amplification in the host cell cytoplasm providing high antigen production against infectious pathogens and various types of cancers, and expression of anti-tumor genes, toxic genes, and immunostimulatory genes. Self-amplifying RNA viral vectors have been evaluated in animal models and clinical trials for immune responses and protection against challenges with pathogenic infectious agents and tumor cells. Likewise, immune responses, tumor regression, and tumor eradication have been monitored in preclinical and clinical settings. The literature search used in the review is based on PubMed and clinical trial/biotechnology company websites up until September 2024. Self-amplifying RNA viruses have elicited strong immune responses and vaccine efficacy in animal models and humans leading to the approval of the vesicular stomatitis virus-based vaccine against Ebola virus disease in both the US and Europe. Moreover, therapeutic and prophylactic efficacy has been demonstrated in animal tumor models and cancer patients. Self-amplifying RNA viruses have also been evaluated in mouse models for neurological disorders.

Protein Expression Platforms and the Challenges of Viral Antigen Production.

Several protein expression platforms exist for a wide variety of biopharmaceutical needs. A substantial proportion of research and development into protein expression platforms and their optimization since the mid-1900s is a result of the production of viral antigens for use in subunit vaccine research. This review discusses the seven most popular forms of expression systems used in the past decade-bacterial, insect, mammalian, yeast, algal, plant and cell-free systems-in terms of advantages, uses and limitations for viral antigen production in the context of subunit vaccine research. Post-translational modifications, immunogenicity, efficacy, complexity, scalability and the cost of production are major points discussed. Examples of licenced and experimental vaccines are included along with images which summarize the processes involved.

Backstage Heroes-Yeast in COVID-19 Research.

The extremely rapid development of understanding and technology that led to the containment of the COVID-19 pandemic resulted from collaborative efforts in the fields of Betacoronavirus pandemicum (SARS-CoV-2) biology, pharmacology, vaccinology, and medicine. Perhaps surprisingly, much of the research was conducted using simple and efficient yeast models. In this manuscript, we describe how yeast, eukaryotic microorganisms, have been used to research this global challenge, focusing on the therapeutic potential of the studies discussed herein. Thus, we outline the role of yeast in studying viral protein interactions with the host cell proteome, including the binding of the SARS-CoV-2 virus spike protein to the human ACE2 receptor and its modulation. The production and exploration of viral antigens in yeast systems, which led to the development of two approved COVID-19 vaccines, are also detailed. Moreover, yeast platforms facilitating the discovery and production of single-domain antibodies (nanobodies) against SARS-CoV-2 are described. Methods guiding modern and efficient drug discovery are explained at length. In particular, we focus on studies designed to search for inhibitors of the main protease (Mpro), a unique target for anti-coronaviral therapies. We highlight the adaptability of the techniques used, providing opportunities for rapid modification and implementation alongside the evolution of the SARS-CoV-2 virus. Approaches introduced in yeast systems that may have universal potential application in studies of emerging viral diseases are also described.

Deep learning-based design and experimental validation of a medicine-like human antibody library.

Antibody generation requires the use of one or more time-consuming methods, namely animal immunization, and in vitro display technologies. However, the recent availability of large amounts of antibody sequence and structural data in the public domain along with the advent of generative deep learning algorithms raises the possibility of computationally generating novel antibody sequences with desirable developability attributes. Here, we describe a deep learning model for computationally generating libraries of highly human antibody variable regions whose intrinsic physicochemical properties resemble those of the variable regions of the marketed antibody-based biotherapeutics (medicine-likeness). We generated 100000 variable region sequences of antigen-agnostic human antibodies belonging to the IGHV3-IGKV1 germline pair using a training dataset of 31416 human antibodies that satisfied our computational developability criteria. The in-silico generated antibodies recapitulate intrinsic sequence, structural, and physicochemical properties of the training antibodies, and compare favorably with the experimentally measured biophysical attributes of 100 variable regions of marketed and clinical stage antibody-based biotherapeutics. A sample of 51 highly diverse in-silico generated antibodies with >90th percentile medicine-likeness and > 90% humanness was evaluated by two independent experimental laboratories. Our data show the in-silico generated sequences exhibit high expression, monomer content, and thermal stability along with low hydrophobicity, self-association, and non-specific binding when produced as full-length monoclonal antibodies. The ability to computationally generate developable human antibody libraries is a first step towards enabling in-silico discovery of antibody-based biotherapeutics. These findings are expected to accelerate in-silico discovery of antibody-based biotherapeutics and expand the druggable antigen space to include targets refractory to conventional antibody discovery methods requiring in vitro antigen production.

Ferroptosis contributes to immunosuppression.

As a novel form of cell death, ferroptosis is mainly regulated by the accumulation of soluble iron ions in the cytoplasm and the production of lipid peroxides and is closely associated with several diseases, including acute kidney injury, ischemic reperfusion injury, neurodegenerative diseases, and cancer. The term "immunosuppression" refers to various factors that can directly harm immune cells' structure and function and affect the synthesis, release, and biological activity of immune molecules, leading to the insufficient response of the immune system to antigen production, failure to successfully resist the invasion of foreign pathogens, and even organ damage and metabolic disorders. An immunosuppressive phase commonly occurs in the progression of many ferroptosis-related diseases, and ferroptosis can directly inhibit immune cell function. However, the relationship between ferroptosis and immunosuppression has not yet been published due to their complicated interactions in various diseases. Therefore, this review deeply discusses the contribution of ferroptosis to immunosuppression in specific cases. In addition to offering new therapeutic targets for ferroptosis-related diseases, the findings will help clarify the issues on how ferroptosis contributes to immunosuppression.

Oceanic Breakthroughs: Marine-Derived Innovations in Vaccination, Therapy, and Immune Health.

The vast, untapped potential of the world's oceans is revealing groundbreaking advancements in human health and vaccination. Microalgae such as Nannochloropsis spp. and Dunaliella salina are emerging as resources for recombinant vaccine development with specific and heterologous genetic tools used to boost production of functional recombinant antigens in Dunaliella salina and Nannochloropsis spp. to induce immunoprotection. In humans, several antigens produced in microalgae have shown potential in combating diseases caused by the human papillomavirus, human immunodeficiency virus, hepatitis B virus, influenza virus, Zika virus, Zaire Ebola virus, Plasmodium falciparum, and Staphylococcus aureus. For animals, microalgae-derived vaccine prototypes have been developed to fight against the foot-and-mouth disease virus, classical swine fever virus, vibriosis, white spot syndrome virus, and Histophilus somni. Marine organisms offer unique advantages, including the ability to express complex antigens and sustainable production. Additionally, the oceans provide an array of bioactive compounds that serve as therapeutics, potent adjuvants, delivery systems, and immunomodulatory agents. These innovations from the sea not only enhance vaccine efficacy but also contribute to broader immunological and general health. This review explores the transformative role of marine-derived substances in modern medicine, emphasizing their importance in the ongoing battle against infectious diseases.

Exogenous or in situ vaccination to trigger clinical responses in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease for which remarkable therapeutic resistance is the norm. Conventional immunotherapies, like immune checkpoint inhibitors, show limited efficacy in PDA due to a remarkably immunosuppressive tumor microenvironment (TME) and systemic inflammation. This review discusses the potential of both exogenous and in situ vaccination strategies to overcome these barriers and enhance anti-tumor immunity in PDA. Exogenous vaccines, including whole-cell, dendritic cell, peptide, and nucleic acid-based vaccines, have shown varying degrees of promise but face challenges related to antigen selection, production complexities, and patient-specific factors. In contrast, in situ vaccination strategies leverage conventional cytotoxic therapies, such as chemotherapy and radiation therapy, to induce immunogenic cell death and modulate the TME with the aim to stimulate anti-tumor immunity. While preclinical studies support the use of in situ vaccination, balancing the stimulatory and inhibitory effects is likely fundamental to eliciting productive anti-tumor responses in patients. Ongoing research seeks to identify new innovative strategies that can harness the endogenous immune response and trigger in situ vaccination. Overall, while both vaccination approaches offer significant potential, further research and clinical trials will be needed to optimize these strategies for improving patient outcomes in PDA.

Prokaryote- and Eukaryote-Based Expression Systems: Advances in Post-Pandemic Viral Antigen Production for Vaccines.

This review addresses the ongoing global challenge posed by emerging and evolving viral diseases, underscoring the need for innovative vaccine development strategies. It focuses on the modern approaches to creating vaccines based on recombinant proteins produced in different expression systems, including bacteria, yeast, plants, insects, and mammals. This review analyses the advantages, limitations, and applications of these expression systems for producing vaccine antigens, as well as strategies for designing safer, more effective, and potentially 'universal' antigens. The review discusses the development of vaccines for a range of viral diseases, excluding SARS-CoV-2, which has already been extensively studied. The authors present these findings with the aim of contributing to ongoing research and advancing the development of antiviral vaccines.

Novel NTCP ligand dimeric bile acid conjugated with ASO reduce hepatitis B virus surface antigen in vivo

Hepatitis B virus (HBV) specifically infects hepatocytes and causes severe liver diseases. However, functional cure is rarely attainable by current treatment modalities. Anti-sense oligonucleotide (ASO), which targets pregenomic RNAs to reduce hepatitis B virus (HBV) antigen production and viral replication, has been studied as a novel treatment strategy for HBV cure and can be conjugated with N-acetylgalactosamine (GalNAc), thereby enhancing hepatocyte uptake via the asialoglycoprotein receptor (ASGPR). In comparison to GalNAc-ASO conjugation, clinical research indicates that unconjugated ASO is more effective in reducing hepatitis B virus surface antigen level. Recent studies have revealed that human sodium taurocholate co-transporting polypeptide (NTCP) is a functional cellular receptor for hepatitis B virus (HBV), and the bivalent bile acid structure may interact with multiple binding sites on NTCP, yielding much stronger interaction and substantially improved binding affinity. In this study, we synthesized NTCP ligand-antisense oligonucleotide (ASO) conjugation and evaluated the potential of antiviral therapy specifically reduction of HBV antigenemia in mice in vivo.

Optimizing antigen preparation for oxalyl-CoA decarboxylase enzyme diagnostic kit and ELISA system cutoff determination.

The prevalence of kidney stone disease is increasing globally, with calcium oxalate stones being the most common type. Oxalyl-CoA decarboxylase (OXC), an enzyme produced by the gut bacterium Oxalobacter formigenes, plays a crucial role in oxalate metabolism. Deficiencies in OXC activity can lead to the accumulation of oxalate, contributing to kidney stone formation. This study aimed to develop a reliable diagnostic assay for OXC by optimizing antigen production and establishing a cutoff value for an enzyme-linked immunosorbent assay (ELISA). We cloned, expressed, and purified recombinant OXC protein in Escherichia coli BL21(DE3), and generated specific polyclonal antibodies in rabbits. The ELISA system was optimized and validated using serum samples from 40 healthy individuals and 6 patients with oxalate-related disorders. The cutoff value was determined using the formula (M + 2SD), where (M) is the mean and (SD) is the standard deviation of the healthy sample results. The calculated cutoff value of 0.656750 effectively distinguished between healthy and affected individuals, with a sensitivity of 97.5% and a specificity of 83.3%. These findings provide a valuable tool for the early detection and management of oxalate-related disorders, with significant implications for clinical practice.

Safety and efficacy of praziquantel in pregnant women infected with Schistosoma haematobium in Lambaréné, Gabon – Clinical results from the randomized, single-blinded, controlled freeBILy-Gabon trial

ObjectivesDespite evidence of praziquantel's (PZQ) safety for treating schistosomiasis in pregnancy, many countries withhold treatment. Only two randomized controlled trials have investigated PZQ in pregnancy, none involving Schistosoma haematobium. MethodsPregnant women during the second trimester in Lambaréné (Gabon) were screened for S. haematobium infection using urine microscopy and circulating anodic antigen detection. Participants positive for either test were randomized (3:1) to single-dose PZQ 40 mg/kg during pregnancy versus no treatment during pregnancy. Investigators were blinded for allocation. Primary outcomes were reduction of egg (egg reduction rate [ERR]) and antigen production (infection reduction rate [IRR]) while explorative outcomes included assessment of cure rate, adverse events, maternal hemoglobin levels, maternal anemia prevalence at delivery, pregnancy outcomes, and newborn anthropometric parameters. ResultsOf 761 women screened 165 were eligible and randomized (intervention n = 124, control n = 41). Of them, 124 completed the study (n = 90 and n = 34, respectively). Treatment led to a significantly higher ERR (95.0% [91-97%] vs 27.0% [−42-63%]) and IRR (95% [91-97%] vs 56% [14-78%]). Common adverse events were dizziness, nausea, and vomiting. Maternal anemia at delivery was significantly lower in the intervention group (odds ratio: 0.40 [0.16;0.96], P = 0.04). No increased risk for adverse pregnancy outcomes was observed. ConclusionsThis first randomized controlled trial investigating PZQ in pregnant women with S. haematobium found PZQ to be safe, effective, and reducing maternal anemia. We recommend treating confirmed infections to prevent morbidity in pregnant women.

CT584 Is Not a Protective Vaccine Antigen against Respiratory Chlamydial Challenge in Mice.

Background:Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen in humans worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and decentralized production of recombinant protein vaccine antigens. Methods: Here, we use CFPS to produce the full-length putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for evaluation as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) (RIBM, Tsukuba, Japan) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four weeks later by an i.m. boost before respiratory challenge with 104 inclusion forming units (IFU) of Chlamydia muridarum. Results: Immunization with CT584 generated robust antibody responses but weak cell-mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lung weights, and the presence of high numbers of IFUs in the lungs. Conclusion: While CT584 was not a protective vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens make it an attractive technique for antigen production.

Sulfate Radical Based In Situ Vaccine Boosts Systemic Antitumor Immunity via Concurrent Activation of Necroptosis and STING Pathway.

In situ vaccine (ISV) can provoke systemic anti-tumor immunity through the induction of immunogenic cell death (ICD). The development of ISV technology has been restricted by the limited and suboptimal ICD driven tumor antigen production which are currently relying on chemo-drugs, photo-/radio-sensitizers, oncolytic-virus and immunostimulatory agents. Herein, a sulfate radical (SO4 ·-) based ISV is reported that accomplishes superior tumor immunotherapy dispense from conventional approaches. The ISV denoted as P-Mn-LDH is constructed by intercalating peroxydisulfate (PDS, a precursor of SO4 ·-) into manganese layered double hydroxide nanoparticles (Mn-LDH). This design allows the stabilization of PDS under ambient condition, but triggers a Mn2+ mediated PDS decomposition in acidic tumor microenvironment (TME) to generate in situ SO4 ·-. Importantly, it is found that the SO4 ·- radicals not only effectively kill cancer cells, but also induce a necroptotic cell death pathway, leading to robust ICD signaling for eliciting adaptive immunity. Further, the P-Mn-LDH can activate the stimulator of interferon genes (STING) pathway to further boost anti-tumor immunity. Collectively, the P-Mn-LDH based ISV exhibited potent activity in inhibiting tumor growth and lung metastasis. When combined with immune checkpoint inhibitor, significant inhibition of distant tumors is achieved. This study underpins the promise of SO4 ·- based vaccine technology for cancer immunotherapy.